1. Field of the Invention
The invention is related to hydraulic steering systems and more particularly to hydraulic steering systems for articulated vehicles. Still more particularly the invention is concerned with hydraulic steering systems which utilize feedback from an articulation angle responsive pump and/or a hydraulic accelerometer.
2. Prior Art
A number of steering systems include non-continuous mechanical elements such as worm gears and sector gears which require adjustment to assure complete travel for the steering system. Such systems do not generally have the capability of significantly modifying vehicle handling characteristics to achieve better handling thereof. A system which would provide complete travel and would allow for a modification of vehicle handling characteristics to achieve better handling would be an improvement over the present systems which have non-continuous mechanical elements.
The prior art also discloses steering systems which have a steering pump and a hydraulic follow up of one sort or another acting on a steering valve. The prior art further teaches the use of an electronic system for developing an understeer situation. Still further the prior art teaches the use of a fluidic accelerometer for developing a control signal related to vehicle acceleration.
Even taking into account all of the many teachings of the prior art, it is clear that the prior art does not teach a hydraulic steering system having a main steering valve that is responsive to a steering pump and a hydraulic accelerometer and in certain embodiments also to an articulation pump. Further, the prior art does not teach a system which has the continuation and smooth adjustment which would be available with a hydraulic steering system having a main steering valve that is responsive to a steering pump and a hydraulic accelerometer and in certain embodiments an articulated angle pump.